Back Inflation BCs

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Zhenqing

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I'm looking into buying an SeaQuest Balance BC. Two questions: 1) having never used a back inflation BC, what should I do to compensate for this when I'm on the surface, and 2) What comments do you have regarding the performance of this BC. I've been told that the way to compensate is by putting weights on the back pockets; however, the weights can not be dumped in the event of an emergency. Someone also mentioned that the danger with a back inflation vest is that the diver can drown if unconscious when you are on the surface since the BC tends to rock you forward putting your face under the water. Any advise on what to do to get used to/compensate for these characteristics? Thank you very much for your comments/advise!
 
Zhenqing:
Someone also mentioned that the danger with a back inflation vest is that the diver can drown if unconscious when you are on the surface since the BC tends to rock you forward putting your face under the water.

A BC is not a life preserver. It is not designed to be one, work like one or look like one. The "push you face down" thing is nonsense promulgated by people who primarily know nothing about back inflation.

The thing that tends to push you forward is the positive buoyancy of the ever popular alum 80.

If you do a search here for " back inflation" you'll find many posts on this subject already.

MD
 
Zhenqing:
I'm looking into buying an SeaQuest Balance BC. Two questions: 1) having never used a back inflation BC, what should I do to compensate for this when I'm on the surface, and 2) What comments do you have regarding the performance of this BC. I've been told that the way to compensate is by putting weights on the back pockets; however, the weights can not be dumped in the event of an emergency. Someone also mentioned that the danger with a back inflation vest is that the diver can drown if unconscious when you are on the surface since the BC tends to rock you forward putting your face under the water. Any advise on what to do to get used to/compensate for these characteristics? Thank you very much for your comments/advise!

Generally, back inflate bc's do require some care and experience. On the surface...it is not a good idea to inflate them all the way...no need to really...plus, it depends on the kind of back inflate bc...some have larger capacities than others.

I use a Dive Rite transpac II and I love it...I love the weight integrated design and I love the option of switching out the wings. I find that back inflate weight integrated bcs provide a more stable platform underwater...my Dive Rite comes with a crotch strap, and it has two big tank bands...the tank and bc remain glued to my back...no jacket style riding up and flopping underwater.

Just my 02
 
The following is from my "Ask RSD" column in the Jan/Feb '00 issue of "Rodale's Scuba Diving". It provides a basic orientation to back inflated v jacket style BCs:

"Back inflated BCs contain air bladders or cells toward the back, rather than toward the front of the torso as in jacket style BCs. This design is more common in high end, technical diving BCs rather than in the generally less sturdy, lighter weight, simpler and less expensive jacket style BCs favored by many warm water recreational divers, although several manufactures do offer back inflated "sport" models. As with all dive gear, you should purchase that BC which fits your diving situation, safety and comfort needs, and budget. Comparing back inflated BCs to jacket style BCs:

Pros: (1) Float the diver in a more aerodynamic position underwater; horizontal with head just slightly higher than feet; (2) Can offer far greater lift capacity, a decided plus for divers who wear lots of weight to submerge, or use large, multiple or heavy cylinders; (3) Many have interchangeable air cells so that you can alter lift capacity to meet changing dive situations; (4) Eliminate the chest squeeze which some find uncomfortable and which can contribute to diver panic; (5) Clear the chest area allowing freer movement and easier access to gear; (6) More often offer a weight integration option with those attendant advantages when used correctly; and (7) Tend to better fit larger physiques and those of unusual proportion.

Cons: (1) Tend to force the face into the water when floating on the surface; (2) Tend to be heavier and have hard pack cylinder mounting plates, making carrying and packing more difficult; (3) Can be a little more difficult to vent; (4) Absence of appreciable chest squeeze can make achieving neutral buoyancy a little more difficult, especially initially; and (4) Can cost from somewhat less to a very great deal more.

Of the cons, having one's head pushed toward the water while on surface understandably causes the most distress to divers, especially those who have not tried or had much experience with back inflated BCs. There are actually a number of ways of dealing with this, possibly the simplest being not overinflating the BC and flipping over and swimming on one's back when on the surface. This has the additional advantage of providing a better field of view and placing the fins in a more effective kicking position. One can also add weights to the rear pockets, cylinder, ankles and other locations, as well as make certain adjustments to the ride of the BC, to compensate for this forward push.

Among back inflated BCs are the DiveRite Transpac, Halcyon, Zeagle Ranger/Tech/Concept, Sea Quest Balance, Oceanic Chute, Aqua Lung Alcyone, Scubapro SeaHawk/Falcon and OMS models.

The BC is a very important piece of gear, and a good one is a substantial investment. After carefully determining your needs and desires, you should research available models to see which best fit your situation, and then actually try out as many as possible."

Hope this gets you started.

DocVikingo
 
DocVikingo:
Cons: (1) Tend to force the face into the water when floating on the surface; (2) Tend to be heavier and have hard pack cylinder mounting plates, making carrying and packing more difficult; (3) Can be a little more difficult to vent; (4) Absence of appreciable chest squeeze can make achieving neutral buoyancy a little more difficult, especially initially; and (4) Can cost from somewhat less to a very great deal more.

DocVikingo

Your advice is incorrect, with the exception of the first part of #2.
 
As mentioned earlier a BC is not a life jacket.
I have no experiance with the model you are looking at.
I dive a Halcyon Pioneer 36.
It fits me like a glove.
It fits me well because it can be adjusted to suit about all body types.
My head rides safely above water unlike some others with poor fits that actually have the shoulder portion of their BC elevated well over their ears during their surface float
I never feel like I'm being pushed face down while on the surface, but to be honest with you when I was doing my research on this subject for myself I was very concerned about that for a while.
Good luck to you.
mech
 
I have a back inflate BC, and I dove a steel tank this weekend. I have to agree with MechDiver. It's the positive bouyency of the AL tank that pushes you forward. They are great underwater and it's the way to go..........
 
I too have a back inflate, which fits me like a glove. But I do have to skull the water to keep from going face down. Maybee its inexperience---I have only been diving since 1977????????

But I love it underwater, more than any BC I have ever used. I have been using this one about 4 years both in the summer as a recreational diver and in winter doing recovery work with a drysuit....

Sonny
 
For those saying it will not put a diver face down, please tell me how the very thing that puts you "in the correct horizontal position" underwater will do anything different at the surface.
 
Yep. A light tank combined with all the weight forward of the wing will make the whole thing push you on you're face.

I don't have that problem but I use a backplate and only have 4 pounds on a belt when diving a single tank.

If it's a problem for you get some of that weight off your belt and put it where it belongs.
 

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